Selective Electrochemical Production of Formate from Carbon Dioxide with Bismuth-Based Catalysts in an Aqueous Electrolyte

Chan Woo Lee, Jung Sug Hong, Ki Dong Yang, Kyoungsuk Jin, Jun Ho Lee, Hyo Yong Ahn, Hongmin Seo, Nark Eon Sung, Ki Tae Nam

Research output: Contribution to journalArticlepeer-review

157 Citations (Scopus)

Abstract

For the efficient electroconversion of CO2 to formate, CO and H2 evolution must be suppressed. Herein, carbon-supported BiOx nanoparticles (BiOx/C) were investigated as a potential candidate for CO2 reduction. In bicarbonate solutions, the BiOx/C catalysts exhibited a high Faradaic efficiency of 93.4% for formate from -1.37 to -1.70 V versus Ag/AgCl with a negligible amount of CO and H2. Stable partial current densities and high Faradaic efficiencies were also achieved in 0.5 M NaCl (12.5 mA cm-2 and 96.0%, respectively). The possible reaction pathways and kinetic parameters of formate formation were examined using systematic electrochemical methods, including Tafel, pH dependence, and in situ X-ray absorption near-edge structure analyses. From the results of these mechanistic studies, we propose that dual mechanisms are functional on the BiOx/C catalysts. Specifically, a two-electron and one-proton transfer reaction to adsorbed CO2 or a chemical proton transfer reaction to CO2- anion are the possible rate-determining steps (RDSs) at low potentials, whereas a one-electron transfer reaction to CO2 is the RDS at high potentials.

Original languageEnglish
Pages (from-to)931-937
Number of pages7
JournalACS Catalysis
Volume8
Issue number2
DOIs
Publication statusPublished - 2018 Feb 2
Externally publishedYes

Keywords

  • bismuth
  • carbon dioxide
  • electrocatalysis
  • heterogeneous catalysis
  • reaction mechanism

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)

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